The Global Positioning System (GPS), the Global Orbiting Navigation Satellite System (GLONASS), and the satellite navigation system GALILEO are examples of Global Navigation Satellite Systems (GNSS). A GNSS utilizes an earth-orbiting constellation of a plurality of satellites each broadcasting GNSS signals which indicates its precise location and ranging information. From particular given locations on or near the earth, GNSS receivers may detect valid GNSS signals using a temperature compensated crystal oscillator (TCXO) and take various GNSS measurements such as pseudorange, carrier phase, and/or Doppler to calculate navigation information such as GNSS receiver positions, velocity, and time.
The GNSS receivers, which comprise GPS, GALILEO and/or GLONASS receivers, may be integrated within or externally coupled to mobile devices for navigation applications such as E911, location-based 411, location-based messaging and/or friend finding. The mobile devices may provide connections to access applications such as route tracking, multimedia communication, song downloading, instant messaging, making phone call, and/or mobile television (TV). Depending on the usage of the mobile devices, multiple technologies such as GNSS, wireless WAN (cellular and/or WiMAX), high-speed wireless LAN (WiFi), short-range wireless (Bluetooth), FM and mobile TV, may be integrated within the mobile devices to support corresponding applications.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.